The thing is, official canon is not decided by the audience but by the creator. G1-G3 are all the canonical gothic story; archolos can only be considered fanfiction by that definition, because whoever has the actual rights to gothic gets to decide the canon. I don't think there is any denying though that everyone who played archolos will see some characters of gothic 1 in a different light going forward, and i honestly will be disappointed if marvins development will not be reflected in the remake ( at which point archolos will be able to be considered canon). you see the sense i'm trying to make here? headcanon/fancanon can differ from official canon, and official canon always requires acknowledgement from official sources.